As the furor over Facebook's experimentation with users' emotions spreads across the web, the most common defense of the social media company's actions is that every other web company is doing the same thing, or something close to it. Google, Amazon, Yahoo, Twitter -- they're all gathering data on how people use their services and how small changes can change people's behavior.

“Name a company that involves a large user base and you will find a research division looking to see how people use their site – Google does it, Twitter, MySpace always did it. Think about Nielsen; we’ve lived our lives knowing that Nielsen looks at how people interact with television shows and what they like or don’t like,” says Karen North, professor of digital and social media at USC’s Annenberg School of Communication.

With this pervasiveness of data and behavior studies at different companies, we decided to take a look at the research divisions at some of the biggest web services - and what kinds of work they're actually doing.

Google

Not suprisingly, Google's research division is expansive and varied, with areas of concentration ranging from its all-important search and ad algorithms, to speech and language processing to cyber-security and privacy. Google shares some similiarities with Facebook, in that they are known for keeping close tabs on their users' data for the purposes of advertising. Their research into web behavior seems to support this comparison. But in terms of manipulating user's content, Google seems to stick to small experiments or changes based on user preferences.

“Google is famous for doing widespread social research on how their website is doing," says Carl D. Howe, vice president of research and data sciences at the Yankee Group. "Now this is not emotional research, it’s ‘Do users prefer a one pixel wide blue bar or two pixel blue bar?’ These are called a/b tests and they run hundreds of them every day and they measure the click throughs as a result.”

Twitter is still figuring out how to sell advertising on its service, so it's no surprise its research division is fairly small compared to other web giants. Most of its research is published in the form of blog posts, and focuses on strategies for advertisers to reach users with targeted content or tweeting around large events. Trying to manipulate Twitter is still a risky proposition, so much of the research remains somewhat vague in comparison to the sophisticated findings coming from companies like Google.